Noise eliminator for machines



Dec. 7

E. B. STIMPSON NOISE ELIMINATOR FOR MACHINES Filed Jan. 27 1925 Patented Dec. 7, 1926.

UNITED STATES PATENT OFFECE.

EDWIN B. STECMPSON, OF BROOKLYN, NEW YORK, ASSIGNOB TO EDWIN B. STIMPSON COMPANY, OF BROOKLYN, NEW YORK.

nors'n ELIMINATOR non ivrnonrnns.

Application filed January This invention relates to devices for eliminating shocks and noise in the operation of machines and particularly for cushioning the return and idle stroke of reciprocating parts.

The invention consists of a shock-absorbing or cushioning device which preferably takes the form of a dash-pot having the plunger element thereof connected to a reciprocating part for cushioning the movement of the part in one or both directions and correspondingly eliminating the noises of operation. An example of machine depending upon the reciprocation of parts having an idle and noisy return motion, is found in the class of rivet setting machines in which a plunger or arbor is reciprocated by means of a foot treadle, the parts being returned through their idling stroke by means of a spring or weight. The action of the spring or weight, operating without restriction, forces the arbor and associated parts to withdrawn position and in so doing, in prior constructions, produced considerable shock and noise.

The dash-pot device may be attached at any convenient location on the machine with either the cylinder or the plunger connected to a moving part and includes valve means for admitting air to the cylinder to facilitate relative movement of the parts during the productive operating movements of the machine.

Other features of the invention will be hereinafter referred to.

In the drawings in which two embodiments of the invention have been selected for illustration, Figure 1 is a view in side elevation and partly in section of a rivet setting machine equipped with a shock absorbing and noise eliminating device embodying the invention.

Figure 2 is a view in vertical section and on an enlarged scale showing the construction of the noise eliminating device shown in Figure 1.

Figure 8 is a view in side elevation of another type of rivet setting machine showing a modified application of the noise eliminating device to the machine.

Referring to the .drawingsj'foramore .detailed description, Figural there isshe'wn a'riv'et setting machine which includes a vertical standard 10 supportingahead '11 in which'an arbor 12'is'n1oun'ted for vertical re- 27, 1925. Serial No. 5,149.

ciprocation toward and from an anvil member 13 supported on a bracket 14 attached to the forward face of the standard 10. The reciprocating arbor 12 is operated by means of a foot treadle 15 forming one terminal of a lever arm 16 pivoted at 17 on the standard 10. The free end of the lever arm 16 is connected through a link 18 with a lever 19 pivoted at 20 between lugs 21 formed on the upper surface of the head member 11-. The free end of the lever 19 has a pivotal connection at 22 with the upper end of the arbor 12.

lVith the construction and arrangement of parts described, depression of the foot treadle 15 conveys motion through the connecting parts to the arbor 12 and produces downward movement thereof to thereby engage the rivet or other device which is positioned for the purpose on the anvil 13 to clinch or otherwise act thereon. In order to retract the parts to an inoperative position a coil spring 23 is connected at one end to a hook 24 projecting from the standard 10 and at the other end to the lever 16 at a point adjacent to the foot treadle 15.

In order to prevent the mechanical shock and objectionable noise which results from the impact of the arbor operating lever 19. with a stop lug 25 on the head 11 at the termination of the return stro e produced by the action of the spring 23, a shock absorbing or cushioning device is so connected to the operating parts as to cushion the impact of the engaging parts at the termination of the A idle or return stroke.

A preferred form of shock absorbing or cushioning device for the purpose takes the form of a dash-pot device including a cylinder member 26. formed integrally in the head portion of the machine shown in Figure 1, and a plunger or piston 27 mounted to reciprocate in the bore of the cylinder and having a linked connection 28 with the arbor operating lever 19 at 29 where it is pivotally connected to the operating link 18.. With this arrangement it will be seen that downward movement of the righthand end 29 of the lever 19 which accompanies the return or upward stroke of the arbor 12 is cushioned by the descent of the plunger '27 into the bore of the cylinder 26 thereby eliminating the clash of contacting parts and'atten'dant noise.

In order to cause the dash-pot device to produce its cushioning effect in one direction onlv of movement of the )lun 'er 27 the plunger has a hollowed-out formation with an air port or passage 30 at the inner end thereof to provide communication between the bore of the cylinder and the interior of the plunger or piston 27. With this construction an unrestricted flow of air through the passage 30 will permit of the ready movement of the piston 2a in the bore of the cylinder 26 without interference with movement of the connected machine parts. Provision is made for restricting the flow of air through the piston into the bore of the cylinder by means of valve ports 31 formed in the wall of the plunger 27 adjacent the outer end thereof, the valve ports being covered or uncovered in accordance with the direction of movement of the plunger by means of a cover cap member 32 which is connect ed through a stem 33 with the operating link 28 already referred to. The cover cap has a cup-shaped formation with a downwardly extending annular flange enclosing the upper end of the hollow plunger 2'? and having a restricted extent of travel longitudinally of the plunger 27 into and out of covering relation to the valve port openings 31. This restricted movement of cover cap 32 with relation to the hollow plunger 27 is provided by means of a connecting pin 34 passing diametrically through the plunger and seated at its ends in the cover cap flange. The pin 3% has vertical movement in the valve port openings 31 through which it passes and which are longitudinally extended in the walls of the plunger 27 to provide the desired extent of vertical movement of the connecting pins 34 therein.

' In the operation of the device, downward pressure on the foot treadle 15 produces corresponding downward movement of the arbor 12, this movement being unimpeded by the dash-pot device for the reason that the lifting of the cover cap in the operative movement of the parts initially uncovers the valve port openings 31 to permit passage of air into and through the plunger 27 and through the port 30 in the further lifting movement of the cap 32 and the plunger 27. Following the completion of the operation of the arbor 12 the treadle 15 is released whereupon the spring 23 ifts the treadle to its elevated pisition thereby bringing about a corresponding elevation of the arbor 12 to its retracted or inoperative position. The return movement of the parts produces in the beginning of the movement a downward movement of the cover cap 32 to a position which closes or covers the valve port 7 openings 31. Continued downward move ment of the cover cap 82 engages and forces the plunger 27 to its lowered position. It will'be noted that downward movement of the plunger 27 takes place with the valve port openings 31 in closed condition so that the movement of the plunger downwardly into the bore of the cylinder is restricted by the trapping of air within the bore of the cylinder and in the hollow interior of the plunger 27 so that there can take place only a slow leakage of the trapped air between the relatively closely fitted engaging surfaces of the piston and cylinder parts. The result is that the returning movement of the parts is cushioned or softened so that the ordinary shock and noise is eliminated as will be clearly seen.

In Fi ure 3 of the drawings a different application of the dash-pot controlling device is shown. In this embodiment of the invention, the cover cap member 32 of the device is connected to a stationary or nonmoving stud 85 formed on the vertical standard 36 of the machine shown in this figure. The cylinder 37 of the dash-pot device shown in Figure 3 is the movable member of the device and is connected at its lower end directly to the treadle lever 38.

In the type of machine shown in Figure 3, the tread-lo lever 38 is connected through a link 39 with an arm L0 having a link connection with a vertically reciprocating arbor There is also a link connection 4st with the link 4-2 for operating rivet feed mechanism 45. A weight 46 mounted on the operating link 39 acts to return the parts to their retractedposition when the toot treadle 47 is released.

In the operation of this machine, the retraction of the parts under the action of gravity on the weight 46 forces the cylinder 37 and contained plunger upwardly with relation to the cover cap 32 thereby closin the valve port openings and producing'the re stricted relative movement of the plunger and cylinder 37 which has eon already described in connection with the devices shown in Figures 1 and 2. The downward movement of the foot treadle 47 to produce an operating movement of the machine parts uncovers the valve port openings in the initial part of the movement and thereby frees the cylinder 37 for ready travel along the surface of the contained plunger.

While the control device referred to has been shown as applied to rivet setting machines, this particular application of the device is for example or illustration only, and it is to be understood that the device is capable of application in many and various other types of machines wherein it is desired to eliminate mechanical shock and noise.

I claim 1. In a shock absorbing device for machines having a part partaking of reciprocating motion, a dash-pot including a member having a socket formed therein and a piston moving in said socket, the socketed member and piston being connected to be moved relatively to each other when the part is reciprocated, said pistonhaving a port adapted to control passage of air to and from the socket, and a member positively moved by operation of the reciprocating part for controlling the port.

2. In a shock absorbing device for machines having a part partaking of reciprocating motion, a dash-pot including a member having a socket formed therein and a piston moving in said socket, the socketed member and piston being connected to be moved relatively to each other when the part is reciprocated, said piston having a port adapted to control passage of air to and from the socket, and a member for controlling the port, the member being moved to control passage of air through the ports before the piston begins to move in the socket.

In a shock absorbing device for machines having a part partaking of reciprocating motion, a dash-pot including a cylinder and a tubular piston connected to be moved relatively to each other when the part is rec-iprocated, said plunger being provided with ports in the side wall adjacent the outer end thereof, and a cover cap movably connected to the outer end of the plunger to open or close the ports in accordance with the direction of relative movement of the plunger and piston.

d. In a shock absorbing device for machines including a reciprocating part having idle movement in one direction, a dash-pot device including a cylinder and a piston connected to said reciprocating part, said piston having an air passage therethrough terminating at the inner end of the piston and at the other end in a port in the side wall adjacent the outer end of the piston, and a cover cap movably connected to the outer end of the piston to open the port in relative ly outward movement of the piston and to close the port in a relatively inward direction of movement of the piston, whereby to restrict relative inward movement of the piston and correspondingly restrict impact of the parts in the idle stroke of the reciprocating part.

5. In a shock absorbing device for mac-hines including a reciprocating part having idle movement in one direction, a dashpot device including a cylinder, a pi ton fitted to the cylinder, said piston being hollow and having a closed inner end provided with a port therein, a port in the'side wall of the piston adjacent the outer end thereof, a cover cap on the outer end of the piston having a limited movement longitudinally of the piston to cover or uncover the port, and a connection between the cover cap and the reciprocating part.

6. In a shock absorbing device for machines including a reciprocating part 1nov able through its useful stroke by the act of an operator, spring means for providing a quick-return movement of the part in its idle stroke, a dash-pot device including a cylinder, a piston fitted to the cylinder, said piston being hollow and having a closed inner end provided with an air port, a port in the side wall of the piston adjacent the outer end thereof, a cover cap attached to and having a limited movement on the outer end of the piston to cover or uncover said port, said cylinder being stationary, and said cover cap :eing connected to said reciprocating part for operation of the piston.

7. In a shock absorbing device for machines including a reciprocating part, a foot treadle connected to said reciprocating part for moving the part through its useful stroke, a weight for providing a quick-return movement of the part in its idle stroke, a dash-pot device including a cylinder, a piston fitted to the cylinder, said piston being hollow and having a closed inner end provided with an air port, a port in the side wall of the piston adjacent the outer end thereof, acover cap attached to and having a limited longitudinal movement on the outer end of the piston to cover or uncover said port, said cover cap being held stationary and said cylinder being connected to the reciprocating part for operation of the device.

8. A dash-pot controlling device compris ing a cylinder, a piston fitted to the cylinder, said piston being hollow and having a clored inner end provided with an air port, a port in the side wall of the piston adjacent the outer end thereof, a cover cap attached to and having a longitudinal movement on the outer end of the piston to cover or uncover said port, and said cover cap and said cylinder being connected to relatively movable parts.

In testimony whereof I aflix my signature.

EDWVIN B. STIMPSON. 

